A PassivHaus home uses 75% less heating energy than a typical UK new-build — roughly £180 saved annually per 100 m².
If you are planning a new home or a major renovation, you have likely come across the term Passivhaus. It is a German-origin building standard that delivers exceptionally low energy bills and high comfort levels. The Passivhaus standard (also spelled PassivHaus) is a voluntary performance-based building certification, not a specific style of house.
A Passivhaus UK home uses 75% less heating energy than a typical new build, saving around £180 per year per 100 m². It is a voluntary, performance-based standard with strict insulation and airtightness targets set by the Passivhaus Institute.
- Save £180 annually per 100 m² on heating compared to UK new builds.
- Heating demand must be ≤15 kWh/m²/yr for Passivhaus certification.
- Air leakage limit is 0.6 air changes per hour at 50 Pa.
- Wall U-value target is ≤0.15 W/m²K, stricter than UK regs.
- Total primary energy demand capped at 120 kWh/m²/yr.
- A PassivHaus home uses 75% less heating energy than a typical UK new-build — roughly £180 saved annually per 100 m².
- Quick numbers — key Passivhaus performance targets
- The eligibility criteria for Passivhaus certification in the UK
- Who can apply for Passivhaus certification — and who cannot
- How to verify an installer and designer for a Passivhaus project
- The role of MCS certification in Passivhaus heating systems
- The financial case — grant eligibility and long-term savings
- How to confirm a Passivhaus project is on track
The standard focuses on ultra-low energy use, high levels of insulation, and airtight construction. It is design-led, not technology-led, meaning it works with any architectural style from a modern box to a traditional cottage. According to the Passivhaus Trust and Energy Saving Trust, a certified Passivhaus home uses roughly 75% less heating energy than a typical UK new-build built to 2026 Building Regulations (Passivhaus Trust, 2026). For a 100 m² home, that translates to annual savings of around £180 on heating alone.
Quick numbers — key Passivhaus performance targets
The Passivhaus Institute sets strict performance targets that every certified building must meet. The table below compares these targets against typical values for a new UK home built to 2026 Building Regulations.
| Metric | Passivhaus target | UK Building Regulations 2026 typical value | Source |
|---|---|---|---|
| Annual heating demand | ≤15 kWh/m²/yr | Approx 50–70 kWh/m²/yr | Passivhaus Institute, 2026 |
| Total primary energy demand | ≤120 kWh/m²/yr | Approx 200–300 kWh/m²/yr | DESNZ Home Energy Model, 2026 |
| Air leakage rate (n50 at 50 Pa) | ≤0.6 air changes per hour | Approx 3–5 air changes per hour | DESNZ Building Regulations, 2026 |
| Wall U-value | ≤0.15 W/m²K | Approx 0.18–0.26 W/m²K | Passivhaus Trust, 2026 |
| Triple-glazed window U-value | ≤0.80 W/m²K | Approx 1.2–1.6 W/m²K | Passivhaus Institute, 2026 |
These targets are not optional for certification. Every metric must be met, and the building is modelled and tested to confirm compliance.
The eligibility criteria for Passivhaus certification in the UK
Certification is available for three types of project: new-build homes, extensions, and deep retrofits under the EnerPHit standard. The building must be designed and modelled using the Passivhaus Planning Package (PHPP) software. This software calculates the energy balance and ensures all performance targets are achievable before construction begins (Passivhaus Trust certification, 2026).
On-site airtightness tests and ventilation commissioning tests are mandatory. If the building fails these tests, the designer must identify leaks and the contractor must fix them before a retest. Certification is only issued once all test results confirm the targets in the table above are met.
Who can apply for Passivhaus certification — and who cannot
Any homeowner, developer, or architect can commission a Passivhaus-certified design. However, certification itself requires the involvement of a certified Passivhaus designer or consultant. These professionals are listed on the Passivhaus Institute and Passivhaus Trust directories (Passivhaus Institute directory, 2026).
Existing homes cannot achieve full Passivhaus certification unless the building is stripped back to the structural frame. For most retrofits, the EnerPHit standard is the correct route. Buildings that rely on oversized active heating systems, such as heat pumps with output far exceeding the heating demand, cannot certify because the standard requires a minimal heating system. Similarly, any building that fails the airtightness test after remedial work cannot achieve certification.
How to verify an installer and designer for a Passivhaus project
The only way to guarantee a genuine Passivhaus is to hire a Passivhaus-certified designer or consultant. You can find them on the Passivhaus Institute database or the Passivhaus Trust certified professionals list (Passivhaus Trust directory, 2026). Builders must follow the certified design exactly. There is no separate “Passivhaus builder” certification, but many experienced builders belong to the Passivhaus Trust Builder Network.
All windows, doors, and mechanical ventilation units must hold Passivhaus Institute component certification. This ensures the products meet the strict U-value and airtightness standards required. If a builder suggests using non-certified components, the project will not pass certification.
How to find a certified Passivhaus designer near you
The role of MCS certification in Passivhaus heating systems
If the Passivhaus design includes a heat pump, the installer must be MCS-certified for the homeowner to access the Boiler Upgrade Scheme (BUS) grant. The BUS provides a grant of £7,500 towards the cost of an air source heat pump (GOV.UK Boiler Upgrade Scheme, 2026). MCS certification is not a Passivhaus requirement, but it is a UK grant-eligibility requirement.
Solar thermal or PV installations on a Passivhaus also require MCS certification for any Smart Export Guarantee payments. Without MCS certification, you cannot receive payments for electricity exported to the grid (MCS, 2026).
The financial case — grant eligibility and long-term savings
Passivhaus itself does not qualify for a specific UK government grant. However, the building’s low energy use makes it eligible for existing schemes. If the design includes a heat pump, you can claim the £7,500 BUS grant. Future home upgrade schemes, such as the Home Upgrade Grant, may also apply to EnerPHit retrofits in eligible areas (DESNZ Home Upgrade Grant, 2026).
The typical construction cost premium for a Passivhaus over a 2026 Building Regulations home is 5–15%. Energy bills are reduced by 70–90% depending on the size and heating system (Passivhaus Trust cost analysis, 2026). The payback period is typically 10–25 years, depending on fuel prices and house size. For a 100 m² home, the annual energy saving of roughly £180 on heating alone, plus savings on hot water and appliances, adds up over time.
Boiler Upgrade Scheme eligibility for Passivhaus homes
How to confirm a Passivhaus project is on track
The designer must produce a PHPP energy model before construction begins. This model is the basis for certification and must be updated if any design changes occur. During construction, an airtightness test is carried out at first fix stage, after the building envelope is complete but before internal finishes are installed. A final airtightness test is performed after completion (Passivhaus Trust certification process, 2026).
The ventilation system (MVHR) must be commissioned to deliver the correct airflow rates per room. The installer should provide a commissioning report showing measured airflow rates against the design values. Without this report, certification will not be granted.
Frequently Asked Questions
Passivhaus is a German-origin building standard that cuts heating energy use by 75% compared to UK new builds. It requires strict targets for insulation, airtightness, and energy demand, as set by the Passivhaus Institute.
Building a Passivhaus in the UK typically costs 10-20% more than a standard new build, according to the Passivhaus Trust. However, annual heating savings of around £180 per 100 m² offset this over time.
Yes, for energy savings and comfort. A Passivhaus uses 75% less heating energy, saving roughly £180 yearly per 100 m², and maintains stable indoor temperatures, as confirmed by the Energy Saving Trust.
Key requirements include heating demand ≤15 kWh/m²/yr, air leakage ≤0.6 air changes per hour, and wall U-value ≤0.15 W/m²K. These are set by the Passivhaus Institute and verified through testing.
Yes, but it is challenging and often more expensive than new builds. The EnerPHit standard is a Passivhaus retrofit option, requiring similar energy targets but with more flexible airtightness limits.
